System of control for electric controllers.



J. H. HALL.

SYSTEM OF CONTROL FOR ELECTRIC CONTROLLERS.

APPLICATION FILED NOV. 27', 1911.

1,062,707. Patnted May 27, 1913.

A TTORNE Y.

4 UNITED STATES PATENT lorries.

JAY H. HALL, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC CONTROLLER ANDMANUFACTURING COMPAN Y, OF CLEVELAND, OHIO, A CORPORATION OF OHIU.

sYs'rnM or common ron ELECTRIC CONTROLLERS.

To all whom it may concern Be it known that I, JAY H.'HALL, a citizenofthe United States, residing at Cleveland, in the county of Cuyahogaand State of Ohio, have invented new and useful Imtric motors,principally thattype in which a manually-operated controller is used inconjunction with automatically operated switches'for governing anelectric motor.-

When starting a motor by-means of a vmanually-operated controller, it ispossible for-the operator'to move his controller too rapidly and causean excessive amount of currentto flow through the motor. A still greatercurrent can be caused toflow if the controller is-moved too rapidly toreverse the motor.

--Among t'heobjects of my invention are to prevent an excessive flow ofcurrent in the motor circuit when a manually-operated controller isusedto govern an. electric motor;,to prevent an excessive amount ofcurrentfiowing in .the mo-tor'circuit when a manually-operatedcontroller is moved too rapidly to reverse a motor; to control thecutting out of certain portions of the resistance' in accordance withthe strength of current flowin'g'in the motor-circuit; and to [preventthe opening of the..magnet1callyoperated switcheswhen current is throughtheir contacts;

- In carrying out'my invention "I provide a manually-operated controllerwhich directly .controlsthe cuttingin of the resistance .in the motor"'circuit,-but which directly con- -trols the cutting out of only 'a'portion of the resistance. Associated with-the controller I provide oneor more magnetically-operated switches for controlling a portion' of the're-. sistance, the operating windings of which are energized 1n certainpositions of the con-' troller by connecting theni'in the motor circuit.

windings is below a certain predetermined ance controlled by theseswitches depends ,7 upon the strength of the current in the'motorcircuit.

To furthenexplain my invention I will re-' vfer to the accompanyingdrawings, Figures Specification t Letters Patent;

These switches are adapted to close their contacts only when the currentin the r Patented May 2'7, 1913.

Annltcation filed November 27, 1911. Serial N 0. 662,590.

1 and 2, which show diagrammatically two forms which my invention mayassume.

, Referring to Fig. 1, -P is a diagrammatic representation oftheordinary drum type controller arr nged to cut in and out of the motoreircuit portions of the resistance. The motor is shown with armature Aand the serles-field winding F. Associated with this controlleris theresistance W, which is arranged to be cut out of the circuitautomatically by the magnetically-operated switch S havingthe'operating-winding C. I'prefer to use for the switch S the type ofswitch disclosed in Ganfields applications, Serial Numbers 583,000,filed September 21, 1910,

'and 604,331, filed January 24,1911, and

Eastwoods Patent, No. 1,040,292, granted October 8, 1912, which switchhas the pe-. culiar characteristic of locking itself open when itswinding is'excited above a predetermined value, and operating to closeits contacts when the excitation, is reduced to or below that value. i Y

The operation of the controller is as follows: Upon moving the manuallyoperated controller P to the position 1, themotor circuit is establishedfrom the positive through the series field F,.the armature A, the entireresistance It. and the resistance WV to the negative. The current inthis circuit starts the motor which then runs at its slowest speed. T 0increase the speed of the motor the controller P is moved to itssuccessive positions 2, 3, 4, etc., gradually cutting out portions ofthe resistance R. \Vhen theposition 8"i's reached, the last'section ofthe resist-' ance'R and the resistance-V constitute the amountofresistance then included in the motor circuit. Upon moving thecont-roller to the position 9 contact is made with the lastcontactfinger D, and the motor circuit now flows from the positivethrough the field F, the armature'A, the finger D, the-operatingwindings C -01'2" the switch S, and the resistance V to the negative.'Thelast section of the resistance R is now short-circu'ited by thewinding C, and practically all of the motor current flows through thewinding C, and if this amount ofcurr'ent is greater than the value atwhich the switch S is adjusted, to operate, the switch S will be lockedopen motor circuit. As soon as the motor current decreases to the valueatwhich the switch S is adjusted to operate, it closes its contacts,

and the resistance V will still remain in the The motor circuit nowcontains only the mo tor windings, the controller contacts, and

' the operating winding of the switch S, and

the motor will operate at its normal fullload speed. When the operatorwishes to slow down or stop the motor, on moving the controller back toposition 8 the circuit through the finger D is interrupted at thecontacts of the controller, and the winding C is thereforedeiinergized-and the switch falls open, inserting the resistance -W inthe motor circuit. U on moving the controller farther toward t eoft-position, more and more ofthe resistance It is inserted in the motorcircuit until the cit-position is reached, whereupon the motor circuitis interrupted at the first two contact fingers of the controller.

If the operator, in starting the motor, moves the controller P to theposition -9 too rapidly, the resistance It is cut out of circuit but theresistance W remains in circuit.

The latter will be so proportioned as to limit the current flowingthrough the motor to a safe value. The switch S remains locked open bythe excessive current through its winding until the current decreases tothe value at which the switch is adjusted to operate, at which timetheresistancc \V is short-circuited. No matter how rapidly the operatoradvances his controller to the full running positipn, the limitingresistance 7 can never be cut out until the motor has reached a properspeed, corresponding to the value of current at which the switch Soperates.

In Fig. 2, P represents the well-known face-plate type of manuallyoperated reversing controller, in which the arm L sweeps over concentricsets of segments adapted to regulate the resistances It and R in themotor circuit. Associated with this controller are four magneticallyoperated switches, two of which, S andS' are arranged to control theresistances XV and W when the motor is connected to run in onedirection; and the switches S and S are adapted to control theresistances NV and WV" when the motor is connected to run in theopposite direction. The switches S to S are of the same type of switchas the switch S described in Fig. l, and in addition to their operatingwindings C to C", the switch S has a holding winding H which is arrangedto be connected in series with the contacts of the switch, and holds theswitch closed after it has been closed by its operating winding C Theswitches S and S" have shunt-wound holding windings it and it. Onetermin of these windings is connectedto the positive main; theotherterminal of each winding is connected to the movable po-rtion'ofthe switch and becomes energized upon the closure of the switch. The

outer row of cont-acts of the controller I", which are connected to theresistance Bf, are cross-connected to the lower row of contacts,asindicated by dotted lines. In like manner,-the contacts connected tothe resistance R are cross-connected to a similar set of contacts, asshownfby dotted lines. The segments 10 and 11, instead of beingcrossconnected, are connected to the operating windings of the switchesS and 8*. A blowout magnet'wit-h the winding B is provided for thecontroller Pf, which is connected in the armature circuit-, andisadapted to ex tinguish any are which is formed atfthe contacts of thecontroller.

Since in the arrangement 'shown in Fig.

2 the controller I is provided forextinguishing any are which may becausedbyv rupturing the motor circuit, it is desirable to confine all ofthe arcing to the contacts on the controller, and prevent any arcing atcontacts of the magnetically operated switches S to sity of providingblow-out magnets for each individual switch, and, with this purpose inThis obviates the neces view,l have so'arranged the connections that themagnetically-operated switches will always be held closed so long ascurrent is passing through their contacts.

The operation of the controller is as follows: On moving the controllerto the first position in the forward direction, indi cated by the line f1", the brushes of the con tactarm L will connect the segments 3 and atand the segments 5 and 6. The motor circuit will then be established asfollows:

from the positive through the field winding' i the contact 1, the crossconnection to the contact the resistance R, the contact 3, the brushesof the arm L, the contact 4, the blowout winding 13, throughthe motorarmature A from right to left, the point 0, the resistances W and W thecontact 5, the brushes of the contact arm L, the contact 6, the crossconnection to the contact 7 the resistance R and the conductors 21 111K22 to the negative. The motor circuit now includes the motor windings,the resistances R and R which are controlled directly by the manuallyoperatedcontroller P, and the resistances iv and W which are controlledby the magnetically-operated switches S". and S The establishment ofthis circuit starts the motor, audit will run at its slowest speed. Onmoving the controller arm in the forward direction, more and more of theresistances R and R is cut outof the circuit, until the position isreached when the righthand arm of the controller rests on the contact 9.Upon moving thecontact arm to the last position, that is, when thecontacts 2 and 4 are connected together, and the contacts .6 and 16, thewinding C of the switch S is included in the motor circuit, and themotor circuit is asfollows: from the posi tive through the field windingF, the contact 1, the cross connection to the cont-act 2, the

resistances W and'W the contact 5, the

brushes of the controllerarm, the contact 10, the conductor 23, thewinding (1, and the the switch S in the motor circuit.

conductor 24: to negative. At this time the resistances R and R are allcut out of the motor circuit, and the current is limited by theresistances W and W If, when the controller arm reaches the contact 10,the

motor current is notv above the value at which the switch Sisadjusted-to close, this switch will close immediately and shortcircuitthe resistance WV at the same time connecting the holding winding H ofthe switch S and the operating winding C of It the cutting out of theresistance W allows the current in the motor circuit to increase abovethe value at which the switch Sis adjusted to operate, this switch willbe locked open until the motor current has decreased to the speed of themotor, he will move his controller-arm toward the off-position. lVhenthebrush of the contact arm leaves the contact 10, the winding C of theswitch S is denergized, but this switch does not fall open, because thewinding H is still in the motor circuit and holds the switch closed. Asthe controller arm is moved toward the off-position more and more of theresistances R andR is inserted in the motor circuit, and when thecontroller arm reaches the oiiposition the motor circuit is interruptedat the contacts of the controller, and the windin'gs H and C aredeeuergized, allowing the switches S and S to open. If the operatormoves his controller arm quickly to the full Oll-pOSll'lOll in theforward direction, he will rapidly cut out the resistances R and ti",but the resistances V and V will remain in circuit and will be cut outautomatically by the operation of the switches S and S the winding C ofthe switch S first locking the switch. open until the motor current isreduced to a certain predetermined value, whereupon the switch S closesand cuts out the resistance T The closure of the switch S? energizes thewinding C of the switch S, as before, and the resistance \V is cut outonly after the motor currenthas again decreased to the proper valueafter the closure of the switch S 'locause the motor to run in theopposite direction, the operator moves the contact arm of the controllerto the direction marked Reverse, and when the arm is in position r F,

switch S in the motor circuit.

the motor circuit is as follows: from positive through the field windingF, the contact 1, the cross-connection to the contact 2, the reslstanceR, the contact 3, the cross-connection to the contact 12, the brushesof'the contact arm L, the contact 13, the point 0, the armature A fromleft to right, the' blow-out winding B, the contact 4, the condoctor 25,the resistances 7 and Vi, theeontact 14, the brushes of the contact arm,the contact 7, the resistance R and the conductors 21 and 22 tonegative; The motor 'moved toward the full on-position, the resistancesR and R are graduallycut out of circuit until the last position isreached,

at which time the right hand endof the contact arm rests on the contact11. The circuit now passes through the contact 11, the conductor 26, thewinding C ofthe switch S and the conductor 22 to negative. If thecurrent in the motor circuit at the time that the winding C is energizedis above the value at which the switch 5 is adjusted to operate, theswitch twill belocked open, but as soon as the motor current decreasesto the value at which the switch is adjusted to operate, it will closeits contacts and will cut out the resistance \V and include the winding0. of the Upon the closure of the switch S its holding wind ing his-energized'from positive through the contacts of the switchto'negative by way of the contact 14-, the brushes of the contact arm L,the contact 11, the conductor 26, the winding C* and the conductor 22.The cutting out of the resistance ll by the elosureiot the switch S*increases the current in the-motor circuit and the switch S willbe'locked open until the currentdea creases to the point at which theswitch S is adjusted to operate, whereuponihis switch will close itscontacts, cut out the resistance w and its own operating winding C, andenergize its holding winding it, the winding 74 being energizedlthroughjthe" same circuit as the winding li "The motor is now connecteddirectly across tlie lline. On moving the controller armtoward theoft-position in order to slow down and stop the motor, the winding C ofthe switch 8" is decnergized but the switch S is held closed by itsholding winding h", and the switch S is held closed by its holdingwinding 71 until the arm the controller reaches the elf-position, atwhich time the motor circuit, as well as the circuit through thewindings la and 71 interrupt ed, and'the switches S and 3 drop open.

In some classes of service, such as the. operation of reversing milltables in steel- "mills, it becomes necessary to quickly reverse a motorand change its motion from full speed in one direction to full speed inthe opposite direction as quickly as possible.

tion as quickly as he can, and with, a controller arranged as shownin'Fig. 2, it will be impossible for the current in the motor circuit toexceed a predetermined value as determined by the resistances V, and \V1fthe motor is runnin in one direction, and

- by the resistances l/ B and W* when the motor is running in theopposite direction;

It oftentimes "happens. with some. con-' motor, a circuit therefor, tworesistances 1n trollers that the time required for moving the controllerarm from the osition f to position r r is less than it takes. or amagnetically operated switch-to fall open, audit is, therefore,desirable that the connections be made-so that a switch which is closedwhen the controller is in the forward position will not be reenergizedand held closed when the controlleris moved quickly within to thereverse position, without at- Ieoting the motor circuit while the motoris running in the reverse direction, or in anyway causing an arc to bedrawn on the contacts of the switches S and S In like mannerthe'contacts and windings (if-the switches S and S are energized onlywhen the controller is moved to operate the motor in the reversedirection I haveshown two methods of holding'the "switches closed whenthe controller arm is oved away from the last position-one by usinga-se-ries holding winding, as inthe case of the switch S the other byusing shunt holding windings, as in the case of switches S and S. Itwill be readily understood that all of the switches may be equipped withshunt holding windings if so desired, or the holding windings on theswitches" S and S? can be replaced by series holding windings connectedas shown and described with regard to the holding winding H 'on theswitch S No matter how rapidly the operator advances his controllerhandle'from the offpo-sition to the full running position in eitherdirection, or moves his controller handle from the full position in onedirection to the full position in the other direction, the currentin themotor circuit is Therefore, theswitches S- S? can take their time inopening when the" controller is moved from the forward 'always limitedby either the resistances 1V, W ,,or W V and these resistances are cutout-of circuit automatically by'means of the magnetically operatedswitches connected thereto and controlled by the current flowing in themotor circuit.

Itwill bev readily understood that only one resistance and itscorresponding automatic switch may be used in either direction ofoperation as the conditions warrant, and that a limiting resistancecontrolled by a magneticall'y-operated switch may be associated with anyof the well-known types of manually-operated controllers.

I claim- 1. In an electric n1otor-control system, a

after the manually-controlled resistance is cut outof the circuit. I

2. In an electric motor-control system, a motor, a circuit therefor,a'res1stance in said circuit, a manually-operated controller for cuttingout the resistance, a second resistance in the circuit, a switch forcutting outthe latter resistance, a winding adapted to control theswitch and be connected in the motor circuit, and a contact on thecont-roller for energizing the winding after the first resistance is cutout.

3. In a motor-control system, an electric motor having'an armature, acircuit therefor, a resistance in said'circuit, a manuallyoperatedcontroller for cutting out the resistance, a second resistance in thecircuit, a switch for cutting out the latter resistance, a windingadapted to control the switch and be connected in the armature circuit,and a contact on the controller for energizing the. winding after thefirst resistance is cut out.

4. In a motor-control system, an electric .mo-tor having a fieldwinding, a circuit therefor, a-resistance in said circuit,-ainanually-operated controller for cutting out the resistance, a secondresistance in the circuit, a switch for cutting out the latterresistance, a winding adapted to control the switch and be connected inthe field circuit, and a contact on the controller for energiz- -ing theWinding after the first resistance is cut out. 4

5. In a motor-control system, an electric motor having an armature and aseries field winding, a circuit therefor,-a resistance in said circuit,a manually-operated controller for cutting out the resistance, a secondresistance in the circuit, a switch for cutting out thelatterresistance, a winding adapted to control-the switch and be connected inthe is out out.

6. In an electric motor-control system, a motor, a circuit therefor, tworesistances in series in the circuit, an operators switch forcontrolling one resistance, a magneticallyoperated switch forcontrolling the other resistance, an operating winding thereforconnected in the motor circuit by the operators switch, and a windingfor holding the switch closed until the motor circuit. is interruptedatthe operators switch.

7. In an electric control system, a circuit, a resistance in thecircuit, a manually-operated controller having a series of contacts forregulating the resistance, a second resistance, a switch forshort-circuiting the latter resistance, an operating winding for theswitch, and means for connecting the winding in the circ'uit when allthe-first resistance is cut out.

8. In an electric control system, a circuit, a resistance in thecircuit, a manually-operated controller having a series of contacts forregulating the resistance, a second resistance, a switch forshort-circuiting the latter resistance, an operating winding for theswitch, means for connecting the winding in the circuit when all thefirst resistance is cut out, and means for holding the switch closeduntil thecircuit through its contacts is opened by movement of thecontroller.

9. In an electric motor-control system, a motor, a circuit therefor, aresistance in the circuit, means under control of the operator forcutting out the resistance, a second resistance, and means preventingthe operator from cutting out the second resistance unless the motorcurrent is below a predetermined value, the second means including amagnetically-operated switch haying'contacts 1n the circuit, and anoperating-winding adapted to be connected in the circuit at the will ofthe operator.

10. In an electric motor-control system, a motor, a circuit therefor aresistance in the motor circuit, a manually-ope 'ated controller forcutting out the resistance, a second resistance in the motor circuit, aswitch for short-circuiting the latter resistance, an operating-windingfor the switch, and means for connecting the winding 1n the motorcircuit at or near the full-on posltion of the controller.

11. In an electric motor-control system, a motor, a circuit therefor, aresistance in the circuit, an operators switch for regulating theresistance, a second resistance, means for cutting out the latterresistance only when the current in the motor circuit is below a certainvalue, the said means comprising a magnetically-operated switch havingcontacts which when closed short-circuit the latter resistance, and anoperating-winding for closing the contacts energized by current in themotor circuit. 7

12. In an electric motor-contr0l system, a IIIOt-OI' EI circuittherefor, a reversing controller for the motor, two resistances, meansfor connecting one resistance in the motor circuit when the motor isconnected to run in one direction and for connecting the otherresistance in the motor circuit when the motor is connected to run inthe opposite direction, a magnetically-operated switch forshort-clrcuiting each resistance, operating windings for the switches,and means .for including the Winding of one switch in the motor circuitwhen the reversing controller is in a running position.-

13. In an electric motor-control system, a motor, a circuit therefor, amanually-operated reversing controller for the motor, two resistances,means for connecting one resistance in the motor circuit when the motoris connected to run in one direction, and for connecting the otherresistance in the motor circuit when the motor is connected to run inthe opposite direction, a magnetically-operated switch forshort-circuiting each resistance, operating windings for the switches,means for connecting one of the operating windings in the motor circuitwhen the controller is in the full on-position in one direction, meansfor including the other of the windings in the motor circuit when thecontroller is in the full on-position in the opposite direction, andmeans for holding the switches closed as long as current flows throughtheir contacts.

11. In a current-varying controller, a circuit, resistance therefor,means for cutting out a portion of the resistance, only when the currentin the circuit is below a certain value, the said means comprising amagnetically-operated switch, a winding for the switch energized by thecurrent in the circuit, a manually-operated controller for regulatingthe resistance, and a contact for energizing the winding in a certainposition of the controller.

Signed at Cleveland, Ohio, this 21th day of November, A. D. 1911.

R. H. BENNETT, H. M. DIEMER.

